New allegations in the case against former Illinois congressman Aaron Schock accuse federal authorities of thievery.

The top lawyer for the House of Representatives claims federal authorities committed crimes so they could accuse Schock of crimes. He said the former district manager for Schock turned to thievery at the behest of federal prosecutors.

House of Representatives General Counsel Thomas Hungar accused federal prosecutors of "an apparent theft" of House records in connection to the Schock fraud case.

A letter sent Wednesday and obtained by the ABC7 I-Team was written to the Acting U.S. Attorney in Central Illinois and copied to the judge in the case and a top Justice Department official. Hungar called the conduct by FBI agents and prosecutors "potentially criminal and unconstitutional."

As the I-Team revealed in March, former Schock aide Bryan Rudolph was enlisted by federal authorities to covertly obtain records from the ex-Peoria congressman's main office in downstate Illinois.

Rudolph has yet to be official named by federal prosecutors, but the I-Team has independently verified his identity. In addition to securing documents from the congressional office after Schock stepped down, Rudolph wore a wire and secretly recorded office conversations - a tactic also criticized as potentially unconstitutional by the congressional attorney.

Even though federal prosecutors have said they don't intend to use Rudolph's evidence against Schock, the House lawyer said he has "serious concerns about improper investigative tactics that were apparently employed by federal officials."

Schock was indicted by a federal grand jury in Springfield last fall on 24 felony counts of expense and finance fraud charges, allegedly pocketing tens of thousands of dollars in improper mileage reimbursements, camera equipment and proceeds from selling tickets to the World Series and Super Bowl. There is a July trial date.

The former Schock staffer who wore a wire and is at the center of this latest controversy did not return messages left by the I-Team. In recent court filings, federal prosecutors have pushed back at allegations anything was done improperly or illegally. Congress and the Justice Department have tangled for decades about how investigations of federal lawmakers should be conducted.